The Clinical Core for this program project grant supports the design, implementation and conduct of clinical trials for the treatment of developmental tumors of childhood, This Program Project proposes to identify new targets for developmental tumors of childhood. While current therapies for these tumors has improved on the past, therapies are very toxic and progress has reached a plateau. The Research Projects include investigation of molecular pathology, alterations related to tumor specific translocations, identification of polymorphisms that affect tumor response and patient toxicity, multi-step targeting to enhance the therapeutic index of monoclonal antibody therapy, and development of adoptive cell therapy directed against tumor related targets. These laboratory based investigations require clinical correlation to validate targets. These clinical correlations require: 1. the enrollment of adequate numbers of patients, 2. the precise characterization of patients at presentation and during treatment, 3. obtaining informed consent from patients to obtain specimens of tumor and normal tissues from patients at regularly scheduled intervals, 4. treatment of patients on consistent, protocol-based, prospective clinical trials testing new diagnostic or therapeutic hypotheses. Such cohorts provide an essential component of planned studies correlating results of molecular and cellular characterizations with ultimate outcome. As the Research Projects identify novel targets, the Clinical Core will support the design and implementation of the novel clinical trials to test the validity of these targets in appropriate patients. Specific Aim 1 involves the recruitment of well characterized patients with developmental tumors of childhood into the clinical trials of the Department of Pediatrics. These patients will be thoroughly characterized at study entry for all relevant clinical and laboratory features. Specific Aim 2 requires obtaining informed consent from patients to obtain tumor and normal tissues at the intervals specified by the clinical trials. Specific Aim 3 requires the treatment of the patients on appropriate hypothesis based clinical trials for which they are eligible. Specific Aim 4 supports the development of novel clinical trials derived from the laboratory investigations proposed in Research Projects 1-4 proposed in this project. The Clinical Core is designed to support the design and implementation of the clinical trials which address the specific aims. This includes constant interaction with the Project Directors of Research Projects 1-4, the Leaders of the Pathology and Biostatistics Cores and support for the clinical trials. The Clinical Core provides the infrastructure for data acquisition, management, and quality control. Research nursing support is provided to ensure timely acquisition of tumor and normal tissue and coordination with Research Projects_